U.S. patent number 4,844,492 [Application Number 07/174,138] was granted by the patent office on 1989-07-04 for two wheeled roller skate.
Invention is credited to Edward E. Ludwig.
United States Patent |
4,844,492 |
Ludwig |
July 4, 1989 |
Two wheeled roller skate
Abstract
A two wheel roller skate has a roller that has two distinct
surfaces consisting of a central part that is a curved surface and
matching right and left frusto conical sections that have an angle
that equals the degree of arc in the central part measured from the
central point of the central part's arc providing greatly improved
maneuverability.
Inventors: |
Ludwig; Edward E.
(Yarmouthport, MA) |
Family
ID: |
26869909 |
Appl.
No.: |
07/174,138 |
Filed: |
March 28, 1988 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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835373 |
Mar 3, 1986 |
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Current U.S.
Class: |
280/11.227;
280/11.233; 301/5.7; 280/11.28 |
Current CPC
Class: |
A63C
17/064 (20130101) |
Current International
Class: |
A63C
17/06 (20060101); A63C 17/04 (20060101); A63C
017/02 () |
Field of
Search: |
;280/11.19,11.22,11.23,11.1BR,11.28,11.1BT,11.25 ;301/5.3,5.7 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1113168 |
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Aug 1961 |
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DE |
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2938316 |
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Apr 1981 |
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DE |
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433586 |
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Apr 1948 |
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IT |
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6241 |
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Jan 1977 |
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JP |
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202577 |
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Apr 1939 |
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CH |
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Primary Examiner: Marmor; Charles A.
Assistant Examiner: Mar; Michael
Attorney, Agent or Firm: Barlow & Barlow
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This appliction is a continuation in part of application Ser. No.
06/835,373 filed Mar. 3, 1986 now abandoned.
Claims
I claim:
1. A roller skating device comprising in combination a supporting
plate for engagement to footwear of a skater and a pair of
longitudinally spaced roller wheel assemblies, each wheel assembly
comprising a hanger having a roller-supporting forked bracket
extending from the plate, resilient mounting means for pivotally
securing each hanger to said supporting plate, and a roller
rotatably secured to said forked bracket, each roller having a
central section with a transversely curved surface and a
frusto-conical end section of decreasing diameter extending from
each side of said central section, the combined length of said
central section and said end sections being substantially greater
than the largest diameter of said central section, wherein the
angle of taper, as measured from a line extending parallel to the
axis of the roller, of each end section is equal to one half of the
arc of curvature of said central section and is also equal to the
angle of inclination occurring at the outer boundary of said
central section.
2. A roller skating device as in claim 1 wherein the arc of
curvature is substantially equal to 22 degrees and the
frusto-conical sections have an angle of taper of substantially 11
degrees from the central section.
Description
BACKGROUND OF THE INVENTION
This invention relates to the art of the two-wheel roller skate. A
review of prior art literature discloses a long history of
worldwide interest and effort in this subject dating from the
earliest days of the roller skate industry and covering a wide
range of skate designs and roller types. Yet, the two-wheel roller
skate has never achieved true success, and the critical problem
still remains, how to make this type of skate fully maneuverable
and safe.
Maneuverability in a roller skate requires an efficient and
reliable system for mechanical turning of the roller assemblies.
This problem was solved in the case of four-wheel skates by the
introduction of the double-action turning mechanism commonly used
in all such skates today. It is a leverage-oriented system ideally
suited to the nature of four-wheel skates where there are two
cylindrical rollers in each roller assembly thus allowing an
optimum degree of lateral roller stability for the skater to work
with in generating the leverage force needed to operate the turning
mechanism.
It is a different matter, however, in the case of two-wheel roller
skates where there is only one roller per assembly thereby severely
limiting the degree of lateral roller stability available to the
skater in producing the necessary leverage force. If a conventional
double-action turning mechanism is to be effectively employed in a
two-wheel roller skate then it is necessary to provide a roller
that can better address the needs for both lateral mobility and
improved lateral stability in a single roller.
In the prior art of two-wheel roller skates, attempts have been
made in the past to arrange a suitable wheel assembly, as for
example, in the Holliday, et al U.S. Pat. No. 4,047,727, where
there is provided a central roller wheel with a pair of
frustoconical independent rotatable end portions. There are other
disclosures in the art of frustoconical rollers, as for example in
the Goodwin Pat. No. 3,282,598 where a single unitary roller
construction is disclosed, the two conical sections of the roller
abutting at the center in a defined V-shaped edge. Other examples
are seen in Japanese Pat. No. 52,6241 to Morita which discloses a
single roller of somewhat barrel shape having one continuous
arcuate surface with recessed grooves therein.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a two-wheel roller
skate having improved rollers with increased lateral stability
contributing directly to improved efficiency in the operation of
the double-action turning mechanism and improved safety and control
in turning maneuvers.
It is a further object of this invention to provide a general
purpose two-wheel roller skate suitable for indoor and outdoor use
on normal skating surfaces, that is practical in respect to
manufacturing means and materials, that would be moderately priced,
easy to operate and provides improved maneuverability.
This invention provides certain improvements in the mechanical
efficiency, operation and performance ability of a two-wheel roller
skate by the employment of improved rollers, based upon the use of
improved dual-surfaced rollers having conically surfaced end parts
providing increased lateral roller stability in combination with an
arcuately surfaced central part providing lateral roller
mobility.
The method of integrating the two distinct surfaces within a single
roller configuration provides that the conically surfaced end parts
extend from the respective bounds of the arcuately surfaced central
section thus extending the angle of inclination occuring at said
bounds throughout the lateral width of the conical end surfaces.
The two distinct surfaces, thus integrated, provide a degree of
ease in the lateral articulation between surfaces that is much
improved over dual-surfaced rollers having a cylindrically surfaced
central part or rollers with only opposing conical surfaces.
The arcuately surfaced central section of the roller provides for
unimpeded mobility in lateral inclination throughout the range of
radial curvature in said central section thus enabling the skater
to shift his or her balance point, as need or desire dictates, to
any point along the lateral width of the central section
surface.
When the rollers are inclined, as in turning maneuvers, to where
the right or left conically surfaced end parts engage the skating
surface, the resulting extended conical surface contact restricts
further inclination of the roller thereby providing increased
lateral roller stability. This increased stability permits a
proportionate increase in the application of lateral turning
pressure by the skater to activate the turning mechanisms resulting
in greater turning force and turning efficiency than is found in
rollers having a continuous radially curved surface.
Of equal importance to maneuverability is the improved traction and
control in turns resulting from the increased amount of frictional
contact provided by the frusto-conical end parts. This improved
traction, together with the angular orientation of the conical
contact, permits the skater to lean into turns in a more natural
skating style and provides substantially more turning control and
safety than is evident in prior art two-wheel roller skates.
This arrangement provides the basis of the roller's surface design
in this method of roller construction and also establishes the
arcuately surfaced central part as the controlling element
effecting surface configuration and related roller function. A
decrease in the degrees of arc will cause a decrease in the angle
of inclination of the end parts and result in increased roller
stability and quicker turning response while producing less
mobility on the central section of the roller. Increasing the
degrees of arc reverses the equation. Small variations in this
respect could find useful application in the design of specialized
rollers for different age groups, skill levels and activities.
The improved roller essentially is particularly designed to engage
a flat skating surface such as in a roller rink and provide
improved lateral stability and improved turning maneuverability and
traction.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a roller skate constructed in
accordance with the invention;
FIG. 2 is a rear elevation of the skate shown in an inclined
position;
FIG. 3 is a sectional view of the hanger and roller assembly taken
on lines 3--3 of FIG. 1; and
FIG. 4 is a diagramatic view showing the development of the surface
of the roller.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1, 10 illustrates a supporting plate of the
roller skate which is fastened to footwear in any suitable manner
(not shown). On the forward end of the supporting plate is a toe
stop 13 that is attached to the supporting plate in any suitable
manner as at 14. Attached to the supporting plate are a pair of
rollers and for convenience only one roller structure will be
described. Each roller has a hanger 16 from which depends, by
suitable fastenings, a pair of brackets 18, 18', that are
illustrated as being made from plastic material for weight
considerations. As will be appreciated the hanger 16 and the
brackets 18, 18' may be formed as a unit out of a single piece of
material. The brackets have an integral arm 17 that leads away from
the main body of the brackets. On the hanger 16 is a pivot post 19
which is adapted for insertion into a pivot post socket such as 21
(see FIG. 3) on the supporting plate 10 with a resilient cushion
19a. The arm 17 is provided with an aperture therein that receives
a bolt 24, the bolt 24 having a tapered cushion 25 thereon, which
cushion is made in two parts, there being also a lower part 26. The
arrangement is such, as well known to those skilled in the art,
that the arm 17 is essentially supported by the resilient cushions
and with the pivot post 19 also supporting the hanger, the two
cooperate so that angular displacement of the roller assembly may
be had.
Mounted on the hanger 16 by an axle bolt 32 is the roller 30 of the
instant invention. The roller is constructed of two parts, there
being an internal part in the form of a rigid core element 31
provided with recesses 33 at the ends thereof into which
anti-friction bearings 36 may be received. The outer surface 31a of
the roller is polyurethane for good wearing ability and is cast
about the core element. As seen in FIG. 4 of the drawings, the
roller that is there illustrated employs a circular arc A-C of 22
degrees and has a 2.68 inch radius; thus, when this is combined
with a roller that has a maximum diameter of 2.5 inches and the
lateral width of approximately 3.125 inch, the central arc portion
subtends a lateral width of approximately 1.0 inch. In the example
given, the chord of arc AC equals 1 inch and the surface of the
conic section equals 1.06 inch. Essentially, there is an arcuately
surfaced central part with conically surfaced end parts and the
conical end parts have their surfaces defined to the central axis
at an angle that is equal to the angle of the arc A-B, thus, arc
A-B equals angle D and arc B-C equals angle D.
The shape of the central section, which has essentially a
symmetrical arcuate surface, provides a running surface on the
central part of the roller that gives an ease of side-to-side
rolling movement on a flat ground surface such as on a roller
skating rink. The running surface of the end parts, which are
conically tapered, provide a resistance to the degree of
inclination of the roller on the flat ground surface, and thereby
provides greater stability in turns, and, in addition, provides a
leverage potential that facilitates right and left turns.
Stated another way, the surface of the central arcuately surfaced
section provides for skating motion in a general forward direction
and provides mobility in right and left hand lateral inclinations.
This allows the skater to shift his balance point on the rollers to
any point along the lateral width of the central part thus, easily
accomodating changes in posture and attitude contributing to
flexibility in skating style. The frusto-conical surfaces provide
the skater with improved lateral stability and with a more stable
roller surface to work with when applying lateral pressure to the
right or left end parts of the rollers. Also the hanger itself is a
lever, more precisely a two sided lever with a double action
turning mechanism centrally mounted thereon. Thus, the hanger with
the roller constitutes a combined roller hanger means for
converting the skater's lateral pressure into leverage forces.
The improved mechanical efficiency described above is responsible
for improved operation of the double action turning mechanism and
consequently, improved turning maneuverability. The improved
operation of the double action turning mechanism is proportionate
to the controlled application of lateral pressure by the skater on
the right or left conically tapered end parts of the rollers in the
execution of right or left turns respectively. An additional major
benefit of the conically tapered end parts of the rollers is the
improved traction and control they provide in turns due to the
increased lateral contact of the rollers with the skating surface
when the rollers are fully inclined in turning maneuvers which
contributes to a safer, more reliable two wheel roller skate.
* * * * *